Four-stroke Cylinder Head Valve Seat Bore Repair

Our reconditioning centre in Vancouver has just carried out furnace brazing of 13 pieces of 32-bore four-stroke engine cylinder heads for Canada’s premier ferry operator.

The valve seat bores were seriously damaged by cavitation and corrosion. Machining to over-size was not possible anymore because this had already been done during past overhauls and the maximum diameter had already been reached.

QuantiServ’s unique process starts with the generous removal of any damaged material around the valve seat bores. Thereafter steel sleeves are soldered in in a vacuum oven before finishing off the heads by NC machining of the valve seat bores. Standard-size valve seats can then be installed, followed by pressure testing of each cylinder head.

QuantiServ’s furnace brazing process is applicable to four-stroke cylinder heads of any engine type with a cylinder bore diameter of > 200 mm. It is patented word-wide and classification approved (LR / ABS). Classification certificates are available on request.

Condition of the cylinder heads before reconditioning:

 

Condition of the cylinder heads after reconditioning, before installation of the valve seats:

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Reconditioning of Two Large Hydraulic Rams in Singapore

Ram 2

In January 2018 our reconditioning centre in Singapore carried out the overhauling and reconditioning of two large hydraulic rams belonging to a major American offshore company. The rams are part of knuckle boom cranes that are installed on an ultra-deep water drill ship that operates off the coast of Myanmar.

We frequently perform this kind of work on rams large and small, often for offshore and construction companies.

The work included chemical stripping of the worn chromium layers, followed by new plating with an underlay of nickel and top-layer of chromium. We also honed the barrel, changed all seals and carried out various NDT tests on the rod and barrel.

All work was carried out in-house and was completed within 14 days.

At QuantiServ Singapore we are able to carry out galvanic nickel and hard-chrome plating and grinding of up to 6,000 mm length and 800 mm diameter.

Update April 2018:

The customer was very satisfied with the two rams that we overhauled for him in January 2018. In March he sent us another two similar ones belonging to the same ship. We have just finished the work on them, which means that we have now reconditioned all four units that are installed on this drill ship.

Reconditioning of Fourteen 96-bore Cylinder Covers

In November 2017, our Reconditioning Centre in Shanghai carried out reconditioning of fourteen cylinder covers for a major European ship owner. These covers came from one of the world’s largest container ships, equipped with a 14-cylinder, 96-bore main engine.

All fourteen cylinder covers and all fourteen exhaust valves were reconditioned within a period of less than one month, while the vessel was undergoing steel work at a shipyard in Qingdao.

This was the third vessel out of a series of similar vessels for the same customer. QuantiServ carried out the reconditioning work for all these vessels.

Significant Reconditioning and Field Service Job in Shanghai

In September our Reconditioning Centre in Shanghai carried out a a major reconditioning and field service order for an Iranian-owned tanker that was docked in a Chinese shipyard. This example shoes well the breadth of QuantiServ’s offering.

The following components were reconditioned:

  • 8 piston rods
  • 7 piston crowns
  • 7 cylinder covers
  • 6 exhaust valves
  • 7 crosshead pins
  • plus a number of smaller, related components

We also sourced for the customer a couple of new crosshead and crankpin bearings while we re-babbitted others, such as for example guide shoes.

QuantiServ engineers also carried out the overhaul work on board, supervised the oil flushing and attended the seatrial after the docking. We also replaced the stern tube shaft seals and in-situ polished some of the crankpin journals.

All the work was completed in 32 days.

QuantiServ at the Norshipping 2017 Exhibition in Oslo

Our participation at the recently held Norshipping 2017 exhibition in Oslo, Norway, was very successful. We displayed our exciting metal stitching, in-situ machining and reconditioning solutions. These solutions created quite a lot of customer interest and led to many interesting discussions. It was also nice to meet many existing customers again and to know some new ones too.

Our next stop will be the Philmarine 2017 exhibition, which will be held from 12 – 14 July 2017 at the SMX Convention Center in Manila. We will be at booth 111/118. Come and visit us there.

QuantiServ at the Sea Asia 2017 Exhibition in Singapore

Sea Asia Exhibition 4Our participation at the recently held Sea Asia 2017 in Singapore was a big success. We displayed our metal stitching and in-situ machining solutions, as well as the refurbishment of four-stroke cylinder covers by furnace brazing, which we are particularly proud of. These solutions created quite a lot of customer interest and led to many interesting discussions.

Our next stop will be the Norshipping Exhibition in Oslo, 30 May – 02 June 2017, where we will be at booth D 05-34. Come and visit us there.

Crank pin machining mock-up

Crank pin in-situ machining mock-up

Furnace brazed 32-bore 4-stroke cylinder cover

Furnace brazed 32-bore 4-stroke cylinder cover

Fully reconditioned 35-bore 2-stroke cylinder cover

Fully reconditioned 35-bore 2-stroke cylinder cover

No job too small – if it solves the customer’s problem

No job too small – if is solves the customer’s problem

A ship’s crew received a new cylinder liner in a mid-eastern port. Unfortunately, while lifting it onto the vessel, a sling came lose and the liner crashed hard on to the deck. Luckily no one was injured, but it caused a piece of cast iron at the circumference to be chipped off, rendering the liner unusable.

Instead of scrapping the liner, the Superintendent contacted QuantiServ and sent us pictures. After we confirmed that we could salvage the liner, he shipped it to our workshop in the Netherlands.

repair-mill

There our skilled machinists milled off a section of the liner and confirmed that there were no further cracks in the material. They then produced on a CNC milling machine a new piece that perfectly resembled the size and shape of the missing material. This they locked in place with glue and screws, thus saving a liner that otherwise would had to be scrapped.